Hey,
My '31 Chevy 5W has a 1979 Cadillac Seville rear with disc brakes and I'd I'd like to hook up emergency brake cables but the calipers do not have the three piece bracket/lever/spring parts needed to do this.
I understand these calipers were unique to 1979 Seville and 1979-81 Firebird with the WS package but was wondering if the three pieces are also unique. In other words do the bracket/lever/spring parts from later calipers fit these calipers?
Thanks
PA Farmer

I believe they don't fit the same. I would suggest going to a junk yard and taking the brackets/ lever, etc off a Cadillac. I'm running the same calipers on my 56 Ford truck. These calipers are very touchy. You have to have a e brake or the adjustment on the pads will go out causing you to have to readjust them. As far as e brake cables. I suggest using the Lokar emegency brake cables. They are costly $120.00, but work nicely with those calipers and look clean underneath. Also check with ECI brakes or steelsolutions.com. They both carry the Cadillac brakes for rear disc conversions. They may be able to get you the brackets you need.

Thanks for the reply.
I've checked with caliper suppliers that include the brake/lever/spring on their calipers but they don't sell them separately. Since I have perfectly good calipers I'm too cheap to buy new ones just for the brackets.
I got a good drawing from our local GM parts man so I guess I need to head to the junkyard and have a look to see if the same setup is used on years other than 1979.
Thanks for the Lokar information as well. I was thinking of going that route although I'm quirky about trying to keep my street junkyard built rather than using aftermarket parts. The Lokar handle/cable setup is tempting though.

Thanks for the reply.
I've checked with caliper suppliers that include the brake/lever/spring on their calipers but they don't sell them separately. Since I have perfectly good calipers I'm too cheap to buy new ones just for the brackets.
I got a good drawing from our local GM parts man so I guess I need to head to the junkyard and have a look to see if the same setup is used on years other than 1979.
Thanks for the Lokar information as well. I was thinking of going that route although I'm quirky about trying to keep my street junkyard built rather than using aftermarket parts. The Lokar handle/cable setup is tempting though.

I believe the rear calipers you are using are for '78 and up GM metric. This should help in your search at the junkyards. Speedway sells them new for $99 each. Part # 910-31046. The Lokar cable hooks up fine. I used the Lokar return spring as well as the GM calipers return spring when installing the Lokar cables to the calipers. The Lokar emergency brake lever (Speedway part # 491-7000) that mounts in the floor and pulls up to engage (Not the one that mounts to the trans like a Model 'A' lever) does NOT have enough mechanical advantage to apply the emergency/parking brake on those calipers. The transmount lever (Speedway part # 491-7016) works well. I had to manufacture a mechanical linkage to increase the leverage when I used the floor mounted lever in my '30 Ford Coupe. I installed it under the car and the cables attached to it at one point while the linkage from the emergency brake handle attached to another point on the linkage. I doubled the mechanical advantage and it then worked fine.

Frisco,
Thanks for the advice. First, I was thinking about using the Lokar floor mount so your tip that it does not have enough mechanical advantage just save me a lot of grief. My '31 is the traditional 350/350 combination so I can easily go with Lokar's transmount. Based on your experience, do I need the 16" for the additional mechanical advantage or will the 11" do?
Also, your pictures were useful. The calipers I have were only used one year on the Seville ('79) and for the 1979-81 Firebird with the WS-6 package but I kinda thought the emergency brake design went well beyond these initial rear disc set-ups. Expanding the junk yard search to include any '78 and up GM metric will make it a lot easier to find the brackets.
Thanks again.

Frisco,
Thanks for the advice. First, I was thinking about using the Lokar floor mount so your tip that it does not have enough mechanical advantage just save me a lot of grief. My '31 is the traditional 350/350 combination so I can easily go with Lokar's transmount. Based on your experience, do I need the 16" for the additional mechanical advantage or will the 11" do?
Also, your pictures were useful. The calipers I have were only used one year on the Seville ('79) and for the 1979-81 Firebird with the WS-6 package but I kinda thought the emergency brake design went well beyond these initial rear disc set-ups. Expanding the junk yard search to include any '78 and up GM metric will make it a lot easier to find the brackets.
Thanks again.

The 16" long lever will work best as is due to the increased mechanical advantage.

I used the 16" lever in the '28 pickup, but it had drum rear brakes and didn't need any additional mechanical advantage.

I have attached a very rough sketch of what I made to increase the mechanical advantage when I used the Lokar floor mount brake lever with the disc rear calipers and built in emergency brake. Left click on it to view a larger image.

I actually welded an 1" diameter X 1" long insert at the pivot point. I drilled and tapped it for a standard zerk fitting and used a bolt that had the full body diameter where it went thru that insert. Because I had previously installed the Lokar rear cables, I had to relocate where they mounted to allow me to install this new linkage. It didn't take very long to fab up and install and worked very well.

Clever setup. If I understand mechanical advantage it looks like you get twice the force on the cables compared with hooking up the cables directly as per Lokar.
I wonder how this compares with the force applied using the transmount? Since I haven't bought anything yet and I have a TH350 I could get their transmount rather than the floor mount.
Any idea idea about the relative pulling force of the transmount compared to the floor mount if hooked up as per instructions from Lokar?

If you can find a 53-56 Ford F100 truck or maybe other vehicles, they have the brake setup similar to the ones the guys are explaing and has a brake lever that mounts underneath the dash. It would be extremely easy to convert to another vehicle. All I had to do was thread in the cables at the connection (T connection) and run one cable to each caliber. Took me less than a half an hour to set up the ebrakes. The thread pattern was the same as well using the Lokar cables. That would be the easier way to setup e brake cables.

Clever setup. If I understand mechanical advantage it looks like you get twice the force on the cables compared with hooking up the cables directly as per Lokar.
I wonder how this compares with the force applied using the transmount? Since I haven't bought anything yet and I have a TH350 I could get their transmount rather than the floor mount.
Any idea idea about the relative pulling force of the transmount compared to the floor mount if hooked up as per instructions from Lokar?

The floormount lever is about 8" long while the transmount lever is 16" long from their respective pivot points. I am not certain whether the length of the linkage below the pivot point on either of those levers is the same or not. Assuming they are, then the obvious advantage is with the 16" long lever.

The simple linkage I fabbed can be used with either setup and as shown will double the mechanical advantage. Altering the dimensions is easily done if more or less mechanical advantage is desired.

As I previously posted, the 16" long transmount lever works as is with drum brakes using Lokar cables. The disc brake calipers with the lever/cam actuating arm requires much more leverage to actually lock up the rear wheels. I assume this is due to their (GM's) design and is amplified when using the short floormount Lokar lever.

I think I've got it.
Now if I could only solve my original problem; finding the brake/spring/lever parts to hook on to my calipers without buying entirely new calipers.
I talked my local GM parts guy and his computer says the part numbers are unique for the 1979 Seville rear and the 1979-81 Firebird rear with the WS-6 package. Looking at the picture from Speedway and others the arrangement on these "GM metric" look exactly the same but the part numbers don't cross.
I guess it's off to the junkyard to get the bracket/spring/lever from one of these GMs and see if it fits despite what GM's computer says.
Too bad it is 15 degrees right now......

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